CDC / RDC · All levels

Reset Deassertion CDC: Review Checklist

Review Checklist for Reset Deassertion CDC.

Review checklist

Review Checklist for Reset Deassertion CDC focuses on reset release violations, metastability-on-release risk, boot instability. The goal is to convert issue observations into mechanism-backed closure decisions.

  • Crossing and reset intent are explicitly classified.

  • Protocol assumptions are documented and checked.

  • Critical issues have owners and dates.

  • Waivers include mechanism, containment, and expiry.

  • Regression matrix includes stress and milestone modes.

  • Owners signed: reset architect, CDC owner, RTL owner.

Signoff ownership

diagram
OWNERSHIP MAP — Reset Deassertion CDC

artifact                  owner
----------------------    -------------------------
design intent           reset architect
verification evidence   CDC owner
signoff decision        RTL owner

Every open CDC/RDC issue needs one accountable owner before waiver or fix.

CDC/RDC deep dive

Reset release ordering is a first-order reliability contract.

Concept diagram

diagram
RESET RELEASE FLOW

assert global -> clocks stable -> sync release per domain -> first transaction

Metric graph

diagram
BOOT STABILITY

passes per 1k boots: 920 -> 980 -> 999

Reports and artifacts

  • reset dependency matrix

  • RDC warning classes

  • boot stress logs

  • waiver aging

Mini case study

Domain B released before producer A was valid, causing rare startup deadlock.

Debug branches

  • Correlate reset and clock timelines

  • verify async assert/sync release

  • exercise skewed release tests

Senior review question

Ask: what evidence proves this risk is closed for silicon, not just tool-clean?

Key takeaways

  • State crossing class, assumptions, and owner with every issue.

  • Run structural and dynamic regressions after each fix.

Common pitfalls

  • Treating all warnings as equivalent risk.

  • Waiving issues without containment evidence.

  • Skipping reset and reconvergence stress after CDC fixes.

Principal CDC/RDC review addendum

Asynchronous assertion is usually safe, but reset deassertion must be synchronized per destination domain to prevent uncertain startup state capture.

Metric: reset release violations, metastability-on-release risk, boot instability